Display help when no option is specified

[nicolasr75]

Using version 2.0:
When the user does not specify any option, I would like to display the same help screen that is automatically shown when the user specifies --help.
I have a very simple program and would like to use as much default behavior as possible. I am using only a few options and this is the code I am using for parsing:

var parserResult = Parser.Default.ParseArguments<CommandlineOptions>(args)

if (parserResult.Tag == ParserResultType.Parsed)
{
    CommandlineOptions options = ((Parsed<CommandlineOptions>)parserResult).Value;

    if(options....)
    {

    }
    ...
    else  //no options specified
    {
        Console.WriteLine(CommandLine.Text.HelpText.AutoBuild(parserResult)); //***
    }       
}

However, the line marked with *** does not work because it expects a NotParsed instance. How could I generate the help output?

[alexanderfast]

Related to #281.

[nemec]

@nicolasr75 see the related question for how to do it without needing a parserResult. Let me know if it works for you!

[nicolasr75]

I put your snippet into my code but it does not compile because of
"TypeInfo does not contain a definition for 'Create'"
Any idea?

[nemec]

Upon further investigation, the TypeInfo class is actually a custom (internal) class, not referring to System.Reflection.TypeInfo at all. Sorry, I guess that doesn't work.